Today, the scientific community comprehensively accepts the viewpoint of the accelerating expansion of the universe and the existing necessity of dark energy. But, if we trace back to the initial theory that ultimately leads to this conclusion, it is the Doppler effect that assumes an equivalence between the frequency shift of the wave sent from an object and the change in the distance between the object and the observer. We argue that, just like the equivalence in Newton's inertia law that cannot apply to all phenomena but is limited to 'macro, low-speed, inertia system', the equivalence behind the Doppler effect also has a corresponding limited application range and the remote object actually exceeds its application range. If we insist on adopting this unsuitable method to measure the change in the relative distance between remote celestial bodies and us, large-scale red shift inevitably misleads us to the cosmic accelerating expansion. To artificially expand the application range of the Doppler effect and force it to apply to all phenomena, we have to assume the whole universe is flooded with a quite high proportion of dark energy that is defined to be incapable of interacting with the electromagnetic wave.